Have you tried running tpm.msc and resetting it? Maybe also try resetting it in the bios/firmware? Those seem to usually do the trick for solving TPM issues.

The issue was actually caused by changing the CPU, the TPM was then reset by the BIOS after the first powerup. I could try it again though.

From my previous experience, Windows will happily insert the decryption key into the TPM once you enter the recovery code.

It usually will but I think there’s something about TPM ownership that sometimes requires manual reset through tpm.msc and/or firmware options.